I have 3 pretty much the same situtation as you the oldest is really laid back and the other 2 are wild as can be lol. I just let them roam free day and night. You should set limits though kinda let them know your in charge or they will take over
I limit them from 2 rooms in the house. They do have accidents sometimes. I heard somewhere its harder to train smaller breeds
Its fun though right? Never a dull moment